Perkins NJ Series Troubleshooting Manual page 127

SENR9982-01
Expected Result:
The connectors and the harness should be free of
the following faults: damage, abrasion, corrosion,
and incorrect attachment.
Results:
• OK – Proceed to Test Step 2.
•
Not OK
Repair: Repair the connectors or the harness
and/or replace the connectors or the harness.
Use the electronic service tool in order to clear all
logged diagnostic codes and then verify that the
repair eliminates the fault.
STOP.
Test Step 2. Check for active Diagnostic
Codes.
A. Turn the keyswitch to the ON position.
B. Use the Perkins EST to check for diagnostic
codes.
Expected Result:
RESULT 1 The Perkins EST displays the following
active diagnostic codes or recently logged diagnostic
codes:
•
91-3 Throttle Position Sensor voltage above normal
• 91-4 Throttle Position Sensor voltage below normal
• 774-3 Secondary Throttle Position Sensor voltage
above normal
• 774-4 Secondary Throttle Position Sensor voltage
below normal
RESULT 2 The Perkins EST displays no active
diagnostic codes:
Results:
• Result 1 – Proceed to Test Step 3.
• Result 2 – Proceed to Test Step 5.
Test Step 3. Check the Throttle Position
with the Perkins Electronic Service Tool
(EST).
A. Connect the Perkins EST to the diagnostic
connector.
B. Turn the keyswitch to the ON position. The engine
should be off.
C. Observe the throttle position reading on the
Perkins EST.
D. Slowly depress the throttle and release the throttle.
Expected Result:
The output should increase when the throttle pedal is
depressed.
The output should be between "20 percent" and "27
percent" at the low idle position. The output should
be between "80 percent" and "87 percent" at the high
idle position.
Results:
•
OK – The sensor is operating correctly. Proceed
to Test Step 4.
• Not OK – The ECM is not receiving a correct
signal from the sensor. Proceed to Test Step 5.
Test Step 4. Check the Throttle Selection
Status with the Perkins Electronic
Service Tool (EST).
A. Check the status of the throttle selection switch (if
equipped). Use the Perkins EST in order to check
the status of the throttle selection switch.
Expected Result:
If the status of the throttle selection switch is shown
in the OFF position, then the throttle 1 has control of
the engine speed.
If the throttle selection switch status is shown in the
ON position, then the throttle 2 has control of the
engine speed.
The throttle may be overridden by using the SAE
J1939 (CAN) data link or the set speed control.
Results:
• OK – The throttle demand switch is operating
correctly.
Repair: There may be an intermittent fault. Refer to
Troubleshooting, "Electrical Connectors - Inspect".
STOP.
• Not OK – The wrong throttle is selected. Change
to the other throttle. There may be a fault with the
selector switch input.
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Troubleshooting Section